When a multi-access-enabled User Equipment (UE) moves from a non-3rd Generation Partnership Project (non-3GPP) network to an area covered by both a non-3GPP network and a 3GPP network, if the UE intends to switch part of services to the 3GPP network and retain the remaining services in the non-3GPP network, the UE initiates connection establishment in the 3GPP network. For example, a multi-access-enabled UE has a Packet Data Network (PDN) connection, and accesses the PDN through a PDN Gateway (PGW). If the UE intends to switch part of services of the PDN connection to the 3GPP network, the UE establishes a new PDN connection in the 3GPP network. If the PGW does not support the multi-access function, the PGW releases resources related to the PDN connection between the UE and the PGW. Consequently, the services not switched to the 3GPP network on the PDN connection are interrupted when the UE uses the multi-access function, and the normal network communication is affected.